After more than three years I've finally managed to visit HMS Belfast, a WWII cruiser which is moored on the Thames, next to the Tower Bridge. The ship has been converted into a floating museum, and it's part of the Imperial War Museums network (being the IWML the main one).
The Belfast was a heavy cruiser in the Royal Navy during the Second World War. Its main tasks were to protect the Atlantic convoy Arctic routes. It is mainly remembered for having participated in the sortie which eventually led to the sinking of the German battleship "Scharnhorst" off the coasts of Norway on the Boxing Day in 1943. This military engagement is quite interesting even from an IT perspective, as it stemmed from the advanced state of the British code breaking and decryption service at that time.
It was in fact mainly due to the work of the mathematicians and cryptographers experts in Bletchley Park on the German ENIGMA encryption method, if the British Navy could stage the ambush to the German battleship (if you are interested I suggest this book as a further reading - or this video for the sinking of the ship).
Back to the floating museum, I think it's worth a visit. It's quite amazing to traverse the various decks of the ship, knowing all the history that every inch of steel there has been testimony of. Up on the bridge, you can also enjoy a breathtaking view of the surrounding landmarks (the Tower Bridge, the Tower of London, the newly built skyscraper Shard of London). You can either wander on the command bridge, or plunge yourself into the hearth of the ship to visit the ammunition storage or the engines, wandering around in steep ladders and tiny corridors. Definitely one of the best attractions I've been in London!
Should you want to see a few of the pictures I've taken, please be my guest here.